On Thu, 21 Dec 2023, Jakub Jelinek wrote:
> Hi!
>
> Multiplication/division/modulo/float operands are handled by libgcc calls
> and so need to be passed as array of limbs with precision argument,
> using handle_operand_addr. That code can't deal with more than one cast,
> so the following patch avoids merging those cases.
> .MUL_OVERFLOW calls use the same code, but we don't actually try to merge
> the operands in that case already.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
> 2023-12-21 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/112941
> * gimple-lower-bitint.cc (gimple_lower_bitint): Disallow merging
> a cast with multiplication, division or conversion to floating point
> if rhs1 of the cast is result of another single use cast in the same
> bb.
>
> * gcc.dg/bitint-56.c: New test.
> * gcc.dg/bitint-57.c: New test.
>
> --- gcc/gimple-lower-bitint.cc.jj 2023-12-20 11:32:45.898425928 +0100
> +++ gcc/gimple-lower-bitint.cc 2023-12-20 12:47:00.168727583 +0100
> @@ -6060,6 +6060,26 @@ gimple_lower_bitint (void)
> || (bitint_precision_kind (TREE_TYPE (rhs1))
> < bitint_prec_large))
> continue;
> + if (is_gimple_assign (use_stmt))
> + switch (gimple_assign_rhs_code (use_stmt))
> + {
> + case MULT_EXPR:
> + case TRUNC_DIV_EXPR:
> + case TRUNC_MOD_EXPR:
> + case FLOAT_EXPR:
> + /* Uses which use handle_operand_addr can't
> + deal with nested casts. */
> + if (TREE_CODE (rhs1) == SSA_NAME
> + && gimple_assign_cast_p
> + (SSA_NAME_DEF_STMT (rhs1))
> + && has_single_use (rhs1)
> + && (gimple_bb (SSA_NAME_DEF_STMT (rhs1))
> + == gimple_bb (SSA_NAME_DEF_STMT (s))))
> + goto force_name;
> + break;
> + default:
> + break;
> + }
> if ((TYPE_PRECISION (TREE_TYPE (rhs1))
> >= TYPE_PRECISION (TREE_TYPE (s)))
> && mergeable_op (use_stmt))
> @@ -6154,6 +6174,7 @@ gimple_lower_bitint (void)
> && (!SSA_NAME_VAR (s) || VAR_P (SSA_NAME_VAR (s))))
> continue;
>
> + force_name:
> if (!large_huge.m_names)
> large_huge.m_names = BITMAP_ALLOC (NULL);
> bitmap_set_bit (large_huge.m_names, SSA_NAME_VERSION (s));
> --- gcc/testsuite/gcc.dg/bitint-56.c.jj 2023-12-20 12:41:28.208398219
> +0100
> +++ gcc/testsuite/gcc.dg/bitint-56.c 2023-12-20 12:38:08.548204489 +0100
> @@ -0,0 +1,129 @@
> +/* PR tree-optimization/112941 */
> +/* { dg-do compile { target bitint } } */
> +/* { dg-options "-std=c23 -O2" } */
> +
> +#if __BITINT_MAXWIDTH__ >= 4096
> +void
> +f1 (_BitInt(4096) *p, int r, _BitInt(115) s, _BitInt(128) t, _BitInt(231) u)
> +{
> + p[0] *= (unsigned _BitInt(2048)) r;
> + p[1] *= (unsigned _BitInt(2048)) s;
> + p[2] *= (unsigned _BitInt(2048)) t;
> + p[3] *= (unsigned _BitInt(2048)) u;
> +}
> +
> +void
> +f2 (_BitInt(4094) *p, int r, _BitInt(115) s, _BitInt(128) t, _BitInt(231) u)
> +{
> + p[0] /= (unsigned _BitInt(2048)) r;
> + p[1] /= (unsigned _BitInt(2048)) s;
> + p[2] /= (unsigned _BitInt(2048)) t;
> + p[3] /= (unsigned _BitInt(2048)) u;
> +}
> +
> +void
> +f3 (_BitInt(4096) *p, int r, _BitInt(115) s, _BitInt(128) t, _BitInt(231) u)
> +{
> + p[0] *= (unsigned _BitInt(2110)) r;
> + p[1] *= (unsigned _BitInt(2110)) s;
> + p[2] *= (unsigned _BitInt(2110)) t;
> + p[3] *= (unsigned _BitInt(2110)) u;
> +}
> +
> +void
> +f4 (_BitInt(4094) *p, int r, _BitInt(115) s, _BitInt(128) t, _BitInt(231) u)
> +{
> + p[0] /= (unsigned _BitInt(2110)) r;
> + p[1] /= (unsigned _BitInt(2110)) s;
> + p[2] /= (unsigned _BitInt(2110)) t;
> + p[3] /= (unsigned _BitInt(2110)) u;
> +}
> +
> +void
> +f5 (unsigned _BitInt(4096) *p, int r, _BitInt(115) s, _BitInt(128) t,
> _BitInt(231) u)
> +{
> + p[0] *= (unsigned _BitInt(2048)) r;
> + p[1] *= (unsigned _BitInt(2048)) s;
> + p[2] *= (unsigned _BitInt(2048)) t;
> + p[3] *= (unsigned _BitInt(2048)) u;
> +}
> +
> +void
> +f6 (unsigned _BitInt(4094) *p, int r, _BitInt(115) s, _BitInt(128) t,
> _BitInt(231) u)
> +{
> + p[0] /= (unsigned _BitInt(2048)) r;
> + p[1] /= (unsigned _BitInt(2048)) s;
> + p[2] /= (unsigned _BitInt(2048)) t;
> + p[3] /= (unsigned _BitInt(2048)) u;
> +}
> +
> +void
> +f7 (unsigned _BitInt(4096) *p, int r, _BitInt(115) s, _BitInt(128) t,
> _BitInt(231) u)
> +{
> + p[0] *= (unsigned _BitInt(2110)) r;
> + p[1] *= (unsigned _BitInt(2110)) s;
> + p[2] *= (unsigned _BitInt(2110)) t;
> + p[3] *= (unsigned _BitInt(2110)) u;
> +}
> +
> +void
> +f8 (unsigned _BitInt(4094) *p, int r, _BitInt(115) s, _BitInt(128) t,
> _BitInt(231) u)
> +{
> + p[0] /= (unsigned _BitInt(2110)) r;
> + p[1] /= (unsigned _BitInt(2110)) s;
> + p[2] /= (unsigned _BitInt(2110)) t;
> + p[3] /= (unsigned _BitInt(2110)) u;
> +}
> +
> +#if __SIZEOF_INT128__
> +void
> +f9 (_BitInt(4096) *p, __int128 r)
> +{
> + p[0] *= (unsigned _BitInt(2048)) r;
> +}
> +
> +void
> +f10 (_BitInt(4094) *p, __int128 r)
> +{
> + p[0] /= (unsigned _BitInt(2048)) r;
> +}
> +
> +void
> +f11 (_BitInt(4096) *p, __int128 r)
> +{
> + p[0] *= (unsigned _BitInt(2110)) r;
> +}
> +
> +void
> +f12 (_BitInt(4094) *p, __int128 r)
> +{
> + p[0] /= (unsigned _BitInt(2110)) r;
> +}
> +
> +void
> +f13 (unsigned _BitInt(4096) *p, __int128 r)
> +{
> + p[0] *= (unsigned _BitInt(2048)) r;
> +}
> +
> +void
> +f14 (unsigned _BitInt(4094) *p, __int128 r)
> +{
> + p[0] /= (unsigned _BitInt(2048)) r;
> +}
> +
> +void
> +f15 (unsigned _BitInt(4096) *p, __int128 r)
> +{
> + p[0] *= (unsigned _BitInt(2110)) r;
> +}
> +
> +void
> +f16 (unsigned _BitInt(4094) *p, __int128 r)
> +{
> + p[0] /= (unsigned _BitInt(2110)) r;
> +}
> +#endif
> +#else
> +int i;
> +#endif
> --- gcc/testsuite/gcc.dg/bitint-57.c.jj 2023-12-20 12:42:12.691772991
> +0100
> +++ gcc/testsuite/gcc.dg/bitint-57.c 2023-12-20 12:42:49.900250015 +0100
> @@ -0,0 +1,21 @@
> +/* PR tree-optimization/112941 */
> +/* { dg-do compile { target bitint } } */
> +/* { dg-options "-std=c23 -O1 -fno-tree-forwprop" } */
> +
> +#if __BITINT_MAXWIDTH__ >= 6384
> +unsigned _BitInt(2049)
> +foo (unsigned _BitInt(6384) x, _BitInt(8) y)
> +{
> + unsigned _BitInt(6384) z = y;
> + return x * z;
> +}
> +
> +_BitInt(2049)
> +bar (unsigned _BitInt(6384) x, _BitInt(1023) y)
> +{
> + unsigned _BitInt(6384) z = y;
> + return x * z;
> +}
> +#else
> +int i;
> +#endif
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
